The present invention provides for a stirrer-feeder for pneumatic seed distributors of the drill type, and which allow an easier functioning even when the seeds are very small, and which assure an even and well-timed sowing.
One of the most important problems concerning seeding (especially intensive cultivations, wherein all the available soil is exploited) is that of uniformly and evenly distributing seeds in the ground.
To this end, seeds should be sown at regular intervals, which is variable according to the kind of cultivation, so as to fill any gap and to avoid waste. In most cases, it is necessary to plant the seeds one by one, without leaving empty areas or planting more than one seed at a time.
To this end, drills are used which are equipped with pneumatic distributors comprising a couple of chambers set one close to the other, separated by a disk that rotates around its axis and is provided with a series of peripheral holes. Seed are put in one of said chambers, while the opposite chamber is kept at a lower pressure, so that seeds are sucked and kept pressed against the holes.
The shape of the chambers is such that this depression is maintained on the whole surface of the disk, except for a small lower area or zone through which seeds pass, falling then on the ground when the holes are in correspondence of said zone. To the rotary disk there are further applied fixed pins that extend towards the seed tank, and act as stirrers. Such devices, however, may present some inconveniences: in fact, very small seeds tend to get stuck in the disk holes, impeding thus the good functioning of the machine.
Moreover, in the quite frequent event where hairy seeds must be sewn, these tend to cling together and to fall in the ground not one by one but in knots, giving rise to the inconveniences.